Biochips are high-tech biological elements designed based on principles of molecular biology, protein chemistry, analytic chemistry and optoelectronics and bioformation, and are manufactured by employing Micro Electro Mechanical System, precision manufacturing and other automatic processes. Their applications cover life science basic research, biomedical diagnosis, new drug discovery, and food safety, and the likes.
The techniques being used include immobilizing biological probes (mainly originating from nucleic acid, protein, carbonhydrate, cells, tissues or the likes) on a substrate, then biological sample solution (such as blood, urine, body fluid, or saliva) containing a target to be tested is mixed on the chip. As the target and the corresponding biological probes have specificity, molecular interactions such as binding reaction or enzyme-catalytic reaction may occur, and resulting in alteration of signals (including optical, piezoelectric, electrochemical, energy signals), or labelling methods such as colormetric, fluorimetric, chemiluminescent or radiative detection may be employed to do image analyses and quantitate optical or radiative intensity of the probe-target complexes to obtain the information of the tested sample.
Many conventional methods for processing biochips such as immobilizing biological probes, mixing sample solution, molecular interaction, and washing and separation are done manually without continuity. They are mostly time-consuming and tedious. The steps used generally include immobilizing biological probes, applying biological sample solution, holding biochips still for molecular interactions for a selected time period, then washing manually and consecutively for a number of times, or utilizing a shaking device to perform mixing operation and manually replacing buffer solution a number of times for washing and separation. The discontinuous operating steps and various devices being used tend to incur problems such as (1) manual control tends to incur time variances, (2) washing by shaking does not have consistent force and tends to damage binding, (3) array spot on the array biochip cannot be anchored and separated properly and may result in solution pollution with each other, (4) washing and removing of solution are not done thoroughly or completely and tend to have residual fluid remained, and (5) scanning is not done timely to detect reaction signals on the array biochip. As a result, errors could incur in signal detection or image analysis.